In practice, with this implementation we never need to make a system call.
We get the main thread's tid (which is the same as our pid) back from
the set_tid_address system call we have to make during initialization.
A new pthread will have the same pid as its parent, and a fork child's
main (and only) thread will have a pid equal to its tid, which we get for
free from the kernel before clone returns.
The only time we'd actually have to make a getpid system call now is if
we take a signal during fork and the signal handler calls getpid. (That,
or we call getpid in the dynamic linker while it's still dealing with its
own relocations and hasn't even set up the main thread yet.)
Bug: 15387103
Change-Id: I6d4718ed0a5c912fc75b5f738c49a023dbed5189
vfork() was removed from POSIX 2008, so this replaces its implementation
with a call to fork().
Bug: 13935372
Change-Id: I6d99ac9e52a2efc5ee9bda1cab908774b830cedc
System calls can be pretty slow. This is mako, which has one of our
lowest latencies:
iterations ns/op
BM_unistd_getpid 10000000 209
BM_unistd_gettid 200000000 8
Bug: 15297299 (kernel panic from too many gettid calls)
Bug: 15315766 (excessive gettid overhead in liblogd)
Change-Id: I49656c0fc5b5d092390264a59e4f2c0d8a8b1aeb
The problem with the original patch was that using syscall(3) means that
errno can be set, but pthread_create(3) was abusing the TLS errno slot as
a pthread_mutex_t for the thread startup handshake.
There was also a mistake in the check for syscall failures --- it should
have checked against -1 instead of 0 (not just because that's the default
idiom, but also here because futex(2) can legitimately return values > 0).
This patch stops abusing the TLS errno slot and adds a pthread_mutex_t to
pthread_internal_t instead. (Note that for LP64 sizeof(pthread_mutex_t) >
sizeof(uintptr_t), so we could potentially clobber other TLS slots too.)
I've also rewritten the LP32 compatibility stubs to directly reuse the
code from the .h file.
This reverts commit 75c55ff84e.
Bug: 15195455
Change-Id: I6ffb13e5cf6a35d8f59f692d94192aae9ab4593d
This reverts commit ced906c849.
Causes issues on art / dalvik due to a broken return value
check and other undiagnosed issues.
bug: 15195455
Change-Id: I5d6bbb389ecefb0e33a5237421a9d56d32a9317c
glibc doesn't have tkill or tgkill and says "use syscall(3) instead".
I've left tgkill since it's quite widely used, but there's no reason
to have tkill as well.
Bug: 11156955
Change-Id: Ifc0af750320086f829bc9914551c172b501f3b60
This was accidentally added at a time when you couldn't add a constant
to <syscall.h> without generating an assembly stub! (You no longer need
to add the constants at all.)
Bug: 11156955
Change-Id: I053c17879138787976c744a5ecf7d30ee51dc48f
The library exists outside bionic. It is dynamically loaded, to replace selected
standard socket syscalls with versions that talk to netd.
Change connect() to use the library if available.
(cherry picked from commit 3a6b627a14df8111b03e452f2df4b5f4938e0e49)
Change-Id: Ib6198e19dbc306521a26fcecfdf6e8424d163fc9
This is a much simpler implementation that lets the kernel
do as much as possible.
Co-authored-by: Jörgen Strand <jorgen.strand@sonymobile.com>
Co-authored-by: Snild Dolkow <snild.dolkow@sonymobile.com>
Change-Id: Iad19f155de977667aea09410266d54e63e8a26bf
Also add the corresponding constant, struct, and function declarations
to <sys/socket.h>, and perfunctory tests so we know that the symbols
actually exist.
Signed-off-by: Guillaume Ranquet <guillaumex.ranquet@intel.com>
Change-Id: Ib0d854239d3716be90ad70973c579aff4895a4f7
This gives us:
* <dirent.h>
struct dirent64
readdir64, readdir64_r, alphasort64, scandir64
* <fcntl.h>
creat64, openat64, open64.
* <sys/stat.h>
struct stat64
fstat64, fstatat64, lstat64, stat64.
* <sys/statvfs.h>
struct statvfs64
statvfs64, fstatvfs64.
* <sys/vfs.h>
struct statfs64
statfs64, fstatfs64.
This also removes some of the incorrect #define hacks we've had in the
past (for stat64, for example, which we promised to clean up way back
in bug 8472078).
Bug: 11865851
Bug: 8472078
Change-Id: Ia46443521918519f2dfa64d4621027dfd13ac566
The situation here is a bit confusing. On 64-bit, rlimit and rlimit64 are
the same, and so getrlimit/getrlimit64, setrlimit/setrlimit64,
and prlimit/prlimit64 are all the same. On 32-bit, rlimit and rlimit64 are
different. 32-bit architectures other than MIPS go one step further by having
an even more limited getrlimit system call, so arm and x86 need to use
ugetrlimit instead of getrlimit. Worse, the 32-bit architectures don't have
64-bit getrlimit- and setrlimit-equivalent system calls, and you have to use
prlimit64 instead. There's no 32-bit prlimit system call, so there's no
easy implementation of that --- what should we do if the result of prlimit64
won't fit in a struct rlimit? Since 32-bit survived without prlimit/prlimit64
for this long, I'm not going to bother implementing prlimit for 32-bit.
We need the rlimit64 functions to be able to build strace 4.8 out of the box.
Change-Id: I1903d913b23016a2fc3b9f452885ac730d71e001
This patch switches to using the uapi constants. It also adds the missing
setns system call, fixes sched_getcpu's error behavior, and fixes the
gensyscalls script now ARM is uapi-only too.
Change-Id: I8e16b1693d6d32cd9b8499e46b5d8b0a50bc4f1d
For 64bit Architectures mmap() is equivalent to mmap64(). This patch
maps mmap64() to mmap() in a similar way to other syscalls that differ
based on the size of off_t and off64_t
Change-Id: If21b21ef71120bad23d9a608d02d4a7de5220a87
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>
Since the ENTRY/END macros now have .cfi_startproc/.cfi_endproc, most of the
custom arm assembly has no unwind information. Adding the proper cfi directives
for these and removing the arm directives.
Update the gensyscalls.py script to add these cfi directives for the generated
assembly. Also fix the references to non-uapi headers to the proper uapi
header.
In addition, remove the kill.S, tkill.S, tgkill.S for arm since they are not
needed at all. The unwinder (libunwind) is able to properly unwind using the
normal abort.
After this change, I can unwind through the system calls again.
Bug: 11559337
Bug: 11825869
Bug: 11321283
Change-Id: I18b48089ef2d000a67913ce6febc6544bbe934a3
The kernel now maintains the pthread_internal_t::tid field for us,
and __clone was only used in one place so let's inline it so we don't
have to leave such a dangerous function lying around. Also rename
files to match their content and remove some useless #includes.
Change-Id: I24299fb4a940e394de75f864ee36fdabbd9438f9
Let the kernel keep pthread_internal_t::tid updated, including
across forks and for the main thread. This then lets us fix
pthread_join to only return after the thread has really exited.
Also fix the thread attributes of the main thread so we don't
unmap the main thread's stack (which is really owned by the
dynamic linker and contains things like environment variables),
which fixes crashes when joining with an exited main thread
and also fixes problems reported publicly with accessing environment
variables after the main thread exits (for which I've added a new
unit test).
In passing I also fixed a bug where if the clone(2) inside
pthread_create(3) fails, we'd unmap the child's stack and TLS (which
contains the mutex) and then try to unlock the mutex. Boom! It wasn't
until after I'd uploaded the fix for this that I came across a new
public bug reporting this exact failure.
Bug: 8206355
Bug: 11693195
Bug: https://code.google.com/p/android/issues/detail?id=57421
Bug: https://code.google.com/p/android/issues/detail?id=62392
Change-Id: I2af9cf6e8ae510a67256ad93cad891794ed0580b
Some MIPS kernels do not correctly restart interrupted system calls that
have been invoked using the indirect syscall (NR_syscall).
The simplest workaround is to handle the indirection in userland and then
call the required system call directly.
Change-Id: I8385399621529db9a52b463c96925f6decaaca30
In practice, thanks to all the registers the stubs don't actually change,
but it's confusing to have an incorrect declaration.
I suspect that fcntl remains broken for aarch64; it happens to work for
x86_64 because the first vararg argument gets placed in the right register
anyway, but I have no reason to believe that's true for aarch64.
This patch adds a unit test, though, so we'll be able to tell when we get
as far as running the unit tests.
Change-Id: I58dd0054fe99d7d51d04c22781d8965dff1afbf3
Unlike on 32-bit systems where off_t is 32-bit, we don't want to
throw away the top 32 bits of an LP64 system's 64-bit off_t.
Change-Id: Ib2e0daeb4fc0b8ab3d1b983d0b371d8f81033b50
This patch adds support for AArch64 to the syscall interface. The kernel
implementation exports a set of canonical syscalls, therefore some of
the userspace exported syscalls are implemented as stubs based on the
canonical set.
Change-Id: Ia965d71e97769b8be9d7655193fc40303964c4df
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>
I've left the exit_group syscall as _exit because otherwise we'd have to
convince the compiler that our _exit (which just calls __exit_group) is
actually "noreturn", and it seems like that would be less clean than just
cutting out the middleman.
We'll just have to trust ourselves not to add anything to SYSCALLS.TXT
that ought to be private but that only has a single leading underscore.
Hopefully we can manage that.
Change-Id: Iac47faea9f516186e1774381846c54cafabc4354
(aarch64 kernels only have the newer system calls.)
Also expose the new functionality that's exposed by glibc in our header files.
Change-Id: I45d2d168a03f88723d1f7fbf634701006a4843c5
Modern architectures only get the *at(2) system calls. For example,
aarch64 doesn't have open(2), and expects userspace to use openat(2)
instead.
Change-Id: I87b4ed79790cb8a80844f5544ac1a13fda26c7b5
Also clean up <signal.h> and revert the hacks that were necessary
for 64-bit in linker/debugger.cpp until now.
Change-Id: I3b0554ca8a49ee1c97cda086ce2c1954ebc11892
This cruft dates from a time when bionic would only output syscall
contants for the syscalls mentioned in SYSCALLS.TXT. I fixed that
a long time ago, but never followed through with the removal of what
was then confusingly called "stub" and was recently renamed "custom".
Change-Id: I8f3872a200b2dc8325e357cc5ee505ea4212ef95
Let's have both use rt_sigprocmask, like in glibc. The 64-bit ABIs
can share the same code as the 32-bit ABIs.
Also, let's test the return side of these calls, not just the
setting.
Bug: 11069919
Change-Id: I11da99f85b5b481870943c520d05ec929b15eddb
